Gas fractionating system



March 1964 E. HELLINGMAN ETAL 3,124,443

GAS FRACTIONATING SYSTEM Filed May 12', 1961 INVENTOR EVERT HELLINGMAN. KLAAS ROOZENDAAL. f3

AGENT United States Patent 3,124,443 GAS FRACTIONATING SYSTEM Evert Hellingrnan and Kiaas Roozendaal, Eindhoven,

Netherlands, assignors to North American Philips Company, Inc., New York, N.Y., a corporation of Delaware Filed May 12, 1961, Ser. No. 109,550 Claims priority, application Netherlands May 17, 1960 4 Claims. (Cl. 6242) The invention relates to a gas fractionating system comprising a vessel to collect liquid gas containing oxygen, a first cooler for gas fed to the fractionating system and a further cooler arranged on the further path of the gas to the fractionating zone and providing a further cooling of the gas.

In such systems great attention should be given to the presence of acetylene in the gas to be fractionated. If acetylene is allowed to accumulate to a given extent and if it comes into contact with liquid oxygen, very dangerous explosions may occur. Static electricity, which may be produced by friction of acetylene particles solidified by freezing and rubbing against a wall, may give rise to sparks, which initiate the explosion. Even shocks or bumps may initiate the explosion, particularly when ozone is dissolved in the liquid oxygen.

It is therefore of paramount importance to keep acetylene away from liquid oxygen which may be collected, for example, in the boiling vessel of an air fractionating column.

The invention provides very simple means to achieve this.

In accordance with the invention the cooler arranged on the path of the gas to the fr-actionating zone is provided with members to retain solid acetylene and other light substances frozen out of the supplied gas.

These members may be formed by gauze, rings or other extensions on the column wall, these members cooling the air and collecting the acetylene separated from the air in the form of snow.

In one embodiment of the invention in which the vessel collecting the \liquid gas is a boil-ing vessel, the first cooler consists of a gauze arranged around the boiling vessel and cooled thereby and the second cooler of a wall of the gas fractionating column, which wall is brushed by the supplied gas on its path towards the column after having passed through the gauze.

The drawing shows diagrammatically a gas fractionating system according to the invention.

FIGURE 1 is an axial sectional view of the lower part of a gas fractionating column.

FIGURE 2 shows the upper part of the column, which is to be considered to be joined to the part of FIGURE 1.

FIGURE 3 is a perspective View of an ecetylene collecting member on the wall of the gas fractionating column.

A boiling vessel 1 supports a cage of upright tubes 2, which communicate on the bottom with a ring duct 3, in which a tube 4 opens out, which conveys liquid gas from a fractionating column to the ring 3, the tubes 2 and the boiling vessel 1.

The column comprises a lower cylindrical part *5 and an upper cylindrical part 6, between which at '7 the supply of the gas to be fractionated enters the open top of cylindrical part 5. The parts 5 and 6 are filled with a packing of Raschig rings, saddle-shaped pieces of gauze or the like.

The cage tubes 2 are surrounded by a cylinder 8 of metal gauze. The gauze may be soldered to the tubes and is strongly cooled by the liquid gas flowing through the tubes.

The boiling vessel 1 has an outlet 9 for gas. The vessel 1 is arranged in a housing .10, to which gas to be frac- 3,124,443 Patented Mar. 10, 1964 tionated is supplied through openings 11 and 12. The water separated out of this gas is collected on the bottom of the housing 10 and conducted away through a duct 13.

Around the tube 4 and the column part 5 is arranged a tube 14. The tube 14 traverses the boiling vessel 1 and is fastened at the bottom to a receptacle 15, provided with annular openings and containing filter material 16. On the outer surface of the tube 14 are provided rings 17, which are made of gauze and which are located in spaced relationship about the lower cylindrical part 5. The shape of the gauze ring may be irregular, which may be achieved by crumpling up a strip of gauze. Through the pipe 18 liquid gas is fed back as a reflux into the column. The liquid is distributed in the column by distributors 19 and 20.

The assembly shown is surrounded, in practice, by a heavy insulation from heat losses. The top part of the column may be connected with the head of a cold-gas refrigerator, which then serves as a source of cold for the gas fractionating column. In this case it is not necessary to supply the gas to be fractionated with a higher pressure than the atmospheric pressure.

The system operates as follows:

The gas to be fractionated is supplied through the openings 11 and '12 into the housing 10. Water is separated out partly by condensation and is collected on the bottom of the housing 10.

The gas encounters on its way to the column first the strongly cooled gauze 8. On this gauze is formed a cake of snow containing crystals of water and carbon dioxide. This cake remains surprisingly pervious to the gas for a long time. The gas is strongly cooled on the gauze 8 and the tubes 2 and flows through the filter 15, 16 upwards into the annular space between the tubes 4 and 14 and between the column parts 5 and 14.

On the wall of the column part 5 the gas is further cooled. In the annular space between the column part 5 and the tube 14- the gas encounters in its flow the gauze rings 17. These rings trap acetylene snow in the spaces of the gauze not yet collected on the cake of snow on the gauze '8 and thus keep the acetylene far remote from the contents of the boiling vessel 1.

Even with high initial concentrations of acetylene in the supplied gas it appears that the gauze S and the rings 17 are so highly eiiective that no dangerous acetylene concentrations occur in the boiling vessel.

The present system may be used for reducing the hazards of other hydrocarbons as well as acetylene.

What is claimed is:

l. A gas fractionating system having a feed gas containing acetylene and producing a product in a liquid state comprising a fractionating column provided at the bottom thereof with a boiling vessel for collecting liquid from said column, a housing having openings therein through which the feed gas to be fractionated is supplied, said boiling vessel being located in said housing, a cage in said housing having a gas permeable wall, said cage depending from and connected to said boiling vessel and being the first cooler for said gas, a second cooler arranged in the path of gas flow toward said fractionating column and cooling the gas further, said second cooler being a plurality of spaced gas-pervious members secured to and in heat exchange with the lower part of said column which collect acetylene and other substances separated out by the freezing of the feed gas flowing through said members, the path of said feed gas being through said openings in said housing, through the gas permeable walls on said cage, along the outer periphery of said column, and through said spaced gas-pervious members secured to said column and into the interior of the latter.

2. A gas fractionating system having a feed gas contain- 6) ing acetylene and producing a product in a liquid state comprising a fractionating column provided at the bottom thereof with a boiling vessel for collecting liquid from said column, a housing having openings therein through which the feed gas to be fractionated is supplied, said boiling vessel being located in said housing, a cage in said housing having a gas permeable Wall, said cage depending from and connected to said boiling vessel and being the first cooler for said gas, a second cooler arranged in the path of gas flow toward said fractionating column and cooling the gas :further, said second cooler being a cooled wall of the lower part of said column having a plurality of gauze rings secured to the outer wall of said column in spaced locations which collect acetylene separated out by the freezing of the feed :gas flowing through said gauze rings, the path of said feed gas being through said openings in said housing, through the gas permeable Wall on said cage, along the outer periphery of said column, and through said spaced gauze rings secured to said column and into the interior of the latter.

3. A gas fractionating system having a feed gas containing acetylene and producing a product in a liquid state comprising a fractionatin-g column, a boiling vessel at the lower end of said column for collecting liquid gas, a housing surrounding said boiling vessel and having openings therein through which the feed gas to be fractionated is supplied, a cage in said housing having a gauze Wall secured thereto which also substantially surrounds said boiling vessel, said cage and gauze wall being cooled by said boiling vessel thereby being the first cooler for the gas to be fractionated, a second cooler formed by a lower portion of the wall of said column and provided with a plurality of spaced gas-pervious members secured to outer portions of said wall and which collect acetylene from the gas traversing therethrough, the path of said feed gas being through said openings in the housing, through the gauze wall on said cage, along the outer periphery of said column and through said spaced, gas pervious members secured to the outer portions of the Wall of said column and into the interior of the latter.

4. A gas fractionating system as claimed in claim 1 wherein said cage includes a plurality of tubes, and a ring duct for receiving the liquid product from said fractionating column, each of said tubes being connected at one end to said boiling vessel and in heat exchanging relationship thereof and connected at the other end to said ring duct, a filter surrounding and connected to at least some of said tubes whereby the gas passes therethrough before entering said column.

References Cited in the file of this patent UNITED STATES PATENTS 1,535,819 Emmet Apr. 28, 1925 1,717,540 Aubert June 18, 1929 2,783,623 Dodge Mar. 5, 1957 2,825,680 Stutz Mar. 4, 1958 2,840,994 Lobo July 1, 1958 2,968,160 Schilling, June 17, 1961 

1. A GAS FRACTIONATING SYSTEM HAVING A FEED GAS CONTAINING ACETYLENE AND PRODUCING A PRODUCT IN A LIQUID STATE COMPRISING A FRACTIONATING COLUMN PROVIDED BOTTOM THEREOF WITH A BOILING VESSEL FOR COLLECTING LIQUID FROM SAID COLUMN, A HOUSING HAVING OPENINGS THEREIN THROUGH WHICH THE FEED GAS TO BE FRACTIONATED IS SUPPLIED, SAID BOILING VESSEL BEING LOCATED IN SAID HOUSING, A CAGE IN SAID HOUSING HAVING A GAS PERMEABLE WALL, SAID CAGE DEPENDING FROM AND CONNECTED TO SAID BOILING VESSEL AND BEING THE FIRST COOLER FOR SAID GAS, A SECOND COOLER ARRANGED IN THE PATH OF GAS FLOW TOWARD SAID FRACTIONATING COLUMN AND COOLING THE GAS FURTHER, SAID SECOND COOLER BEING A PLURALITY OF SPACED GAS-PERVIOUS MEMBERS SECURED TO AN IN HEAT EXCHANGE WITH THE LOWER PART OF SAID COLUMN WHICH COLLECT ACETYLENE AND OTHER SUBSTANCES SEP- 